下载MySQL的yum源

wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm

rpm -ivh mysql57-community-release-el7-8.noarch.rpm

yum install mysql-server

mysql -uroot -proot

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

service mysqld restart

cat /var/log/mysqld.log | grep password

mysql -uroot -p

set global validate_password_policy=0;

set global validate_password_length=4;

alter user 'root'@'localhost' identified by 'root’;